Ear-nose-throat (ent) hollow guidewire with balloon

ABSTRACT

A medical probe includes a hollow guidewire, a balloon, and a magnetic position sensor. The hollow guidewire is configured for insertion into a channel of an organ of a patient. The balloon is fixed to a distal end of the hollow guidewire, is configured to be inserted into the channel using the hollow guidewire, and is further configured to be inflated by pumping of fluid through the hollow guidewire. The magnetic position sensor is fitted at the distal end of the hollow guidewire.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.16/234,601, filed on Dec. 28, 2018, priority of which is hereby claimed.

FIELD OF THE INVENTION

The present invention relates generally to medical probes, andparticularly to ear-nose-throat (ENT) catheters.

BACKGROUND OF THE INVENTION

Various probes have been proposed for ear, nose, and throat (ENT)therapeutic procedures. For example, U.S. Patent Application Publication2010/0198191 describes methods and systems for accessing a Eustachiantube of a patient. The system includes a guide configured for passinginto a nasal passage of the patient to position a distal tip of thecatheter at or near a Eustachian tube, the guide having a distal tipwith a bend having an angle between 30 and 90 degrees; and a guidewireconfigured to pass through the guide into the Eustachian tube. A devicefor providing therapy to the Eustachian tube is passed through theguide. In an embodiment, a dilating balloon is being introduced over aguidewire.

As another example, U.S. Patent Application Publication 2015/0202089describes an apparatus comprises a shaft, an expandable dilator, and atleast one ventilation pathway. The shaft defines a longitudinal axis andcomprises distal and proximal ends with at least one shaft lumen. Theexpandable dilator comprises body with its own proximal and distal ends.The body is configured to transition between a contracted state and anexpanded state. The body is configured to dilate a Eustachian tube of apatient in the expanded state. In some embodiments, one or more feature,dimension or the like of such catheters may be altered to facilitate useof the balloon catheter in a Eustachian tube.

U.S. Patent Application Publication 2013/0274715 describes a device andmethod for dilating a Eustachian tube of a patient. The device includesa guide catheter and a balloon dilation catheter. The balloon dilationcatheter has an actuator that prevents injury to the middle ear. Theballoon dilation catheter is slidably coupled with the guide catheterthrough the guide catheter lumen and is fully inserted into the guidecatheter lumen when the distal side of the actuator is adjacent to theproximal end of the guide catheter. The method involves advancing theguide catheter and balloon dilation catheter through a nasal passage ofthe patient to dilate a portion of the Eustachian tube.

U.S. Patent Application Publication 2018/0036009 describes a method thatincludes inserting into a patient organ a catheter including a positionsensor, a device and a handle. The position sensor is attached to adistal end of the catheter. The device is movable along the catheter.The handle includes a control for navigating the device along thecatheter to a target location in the patient organ. Based on a locationof the position sensor, a target position of the control on the handlethat corresponds to the target location of the device is estimated. Amarker is set to mark the target position of the control on the handle,and the device is navigated to the target location by setting thecontrol to the marker. In an embodiment, the handle comprises a balloonslider, which is configured to move a balloon along a guidewire, so asto position the balloon at a location of treatment.

SUMMARY OF THE INVENTION

An embodiment of the present invention provides a medical probeincluding a hollow guidewire, a balloon, and a magnetic position sensor.The hollow guidewire is configured for insertion into a channel of anorgan of a patient. The balloon is fixed to a distal end of the hollowguidewire, is configured to be inserted into the channel using thehollow guidewire, and is further configured to be inflated by pumping offluid through the hollow guidewire. The magnetic position sensor isfitted at the distal end of the hollow guidewire.

In some embodiments, the hollow guidewire includes a coil-reinforcedpolyimide polymer tube. In some embodiments, the hollow guidewireincludes a braid-reinforced polymer tube. In an embodiment, a distaledge of the hollow guidewire protrudes beyond the balloon.

In another embodiment, the magnetic position sensor is formed on aflexible printed-circuit-board wrapped around the distal end of thehollow guidewire.

There is additionally provided, in accordance with an embodiment of thepresent invention, a manufacturing method, including providing a hollowguidewire for insertion into a channel of an organ of a patient. Aballoon is attached to a distal end of the hollow guidewire so that thehollow guidewire protrudes beyond the balloon. A magnetic positionsensor is fitted at the distal end of the hollow guidewire.

In some embodiments, providing the hollow guidewire includes providing acoil-reinforced polymer tube. In some embodiments, providing the hollowguidewire includes providing a braid-reinforced polymer tube.

In an embodiment, the distal edge of the hollow guidewire protrudesbeyond the balloon and both ends of the balloon are secured to thedistal end of the hollow guidewire. In another embodiment, the methodincludes securing both ends of the balloon to the hollow guidewire bygluing both ends of the balloon to the hollow guidewire. In someembodiments, the method includes securing both ends of the balloon tothe hollow guidewire by melting both ends of the balloon to the hollowguidewire.

In an embodiment, fitting the magnetic position sensor includes formingthe magnetic position sensor on a flexible printed-circuit-board wrappedaround the distal end of the hollow guidewire.

There is further provided, in accordance with an embodiment of thepresent invention, a method, including inserting a balloon attached to ahollow guidewire into a channel of an organ of a patient, wherein theballoon is configured to be inflated or deflated through one or moreside holes in the hollow guidewire. The balloon is navigated in thechannel using a magnetic sensor fitted at the distal end of the hollowguidewire. The balloon is inflated by pumping fluid through the hollowguidewire to dilate the channel.

In some embodiments, the method further includes deflating the balloonthrough the hollow guidewire, and retracting the balloon by pulling thehollow guidewire out of the organ of the patient.

The present invention will be more fully understood from the followingdetailed description of the embodiments thereof, taken together with thedrawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, pictorial illustration of an ear, nose, andthroat (ENT) catheterization system, in accordance with an embodiment ofthe present invention;

FIG. 2 is a side-view of the distal end of the ENT probe of FIG. 1inside a eustachian tube, in accordance with an embodiment of thepresent invention;

FIG. 3 is a schematic, pictorial illustration of the distal end of theENT probe of FIG. 2, in accordance with an embodiment of the presentinvention;

FIG. 4 is a flow chart that schematically illustrates a manufacturingmethod of the ENT probe of FIG. 3, in accordance with an embodiment ofthe present invention; and

FIG. 5 is a flow chart that schematically illustrates a method fordilating an ENT channel, in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION OF EMBODIMENTS Overview

An unusually narrow channel in a patient's head may cause, or worsen, anear, nose, and throat (ENT) medical condition. For instance, aeustachian tube may be exceptionally narrow, and/or may be blocked bywax, which may cause repeated ear infections. As another example, thetear ducts also include very narrow channels that may benefit from beingenlarged. These, and other related ENT medical conditions, may berelieved by dilating the blocked channel. However, there is no easy wayto enlarge such channels at present.

Embodiments of the present invention that are described hereinafterprovide an ENT probe that has an exceptionally small diameter, on theorder of several hundred microns. The disclosed ENT probe is intended tobe used in narrow channels such as the tear ducts, channels in thebrain, channels in the sinuses and the eustachian tube.

Typically, the distal end of the probe is advanced through a smalldiameter sheath (e.g., in a range of 300-500 microns) to provide theprobe passage with sufficient maneuverability in the narrow channel. Theprobe is made of a hollow guidewire with a miniature “plasty” balloondirectly attached to the distal end of the guidewire, enabling ballooninflation up to a diameter of few millimeters. In the present context,the term “plasty balloon” (as opposed to an elastic balloon) means thatonce inflated, the balloon remains in its dilated form and approximatesize even when internal pressure is increased.

The disclosed guidewire is hollow in order to inject (e.g., pump) and/orwithdraw fluid used to inflate and/or deflate the balloon. In someembodiments, holes are made in the walls of the balloon where theballoon is fitted over the distal end of the hollow guidewire. Thedistal edge of the hollow guidewire protrudes beyond the balloon, andthe distal end of the hollow guidewire is fixed (e.g., glued) to theballoon at a proximal end and distal end of the balloon over a perimeterof the hollow guidewire. The balloon is pumped through one or more sideholes in the hollow guidewire, so as to contain the high fluid pressuresinside the balloon, as is typically necessary in plastic dilationprocedures.

In some embodiments, the hollow guidewire wall is made of acoil-reinforced thin-wall polyimide polymer tube. The metal wire in thepolyimide wall, or other suitable plastic, serves to limit expansion ofthe tube due to high internal pressures while not limitingmaneuverability. Such a reinforced tube can withstand the high pressureof fluid being streamed inside the tube during a dilation procedure.Alternatively, the tube may be reinforced with a braid rather than acoil.

In some embodiments, the disclosed ENT probe includes a magneticposition sensor at its distal end, which is used for tracking thelocation of the distal end in the head during the ENT procedure. Themagnetic position sensor may contain a single-, double-, or triple-axismagnetic transducer, and may assist, for example, in positioning theballoon at a target location for dilation in the channel.

In some embodiments, in order to conform with the small diameter sheath,the magnetic position sensor is formed on a flexible printed circuitboard (PCB) wrapped around the ultra-thin hollow guidewire. A similarmagnetic position sensor, which is formed on a flexible PCB wrappedaround a distal end of a sheath of a catheter, is described in U.S.Provisional Patent Application 62/675,952, filed May 24, 2018, entitled“Position Sensor on Brain Clot Sheath and Location Pad Collar,” which isassigned to the assignee of the present patent application and whosedisclosure is incorporated herein by reference.

The disclosed hollow guidewire attached to a dilation balloon which isdilated by streaming high-pressure fluid via the ultra-thin guidewire,may enable minimally invasive ENT treatments that larger diameter probescannot perform.

System Description

FIG. 1 is a schematic, pictorial illustration of an ear, nose, andthroat (ENT) catheterization system 20, in accordance with an embodimentof the present invention. System 20 comprises a probe that is configuredand used, by way of example, to dilate a eustachian tube of a patient 22at a given location over the eustachian tube, as described below.

A processor 40 of system 20 registers, with a coordinate system ofsystem 20, frames of reference of a CT (computerized tomography) imageof patient 22 comprising an image of the eustachian tube. Data of the CTimage is stored in memory 42 for subsequent retrieval by processor 40.

During the exemplified balloon dilation procedure, and as shown in inset25, a magnetic tracking sub-system 23 of system 20 tracks a position ofmagnetic position sensor 32 inside eustachian tube 36 of patient 22. Inparallel, processor 40 registers the magnetically tracked position withthe CT images. As further shown in inset 25, magnetic position sensor 32is fitted at the distal end of the hollow guidewire by wrapping sensor32 around a hollow guidewire 62 at a distal end 34 of ENT probe 28, justproximally to a dilation balloon 60.

Magnetic tracking sub-system 23 comprises a magnetic radiator assembly24, which is positioned beneath the patient's head. Assembly 24comprises magnetic field radiators 26 which are fixed in position andwhich transmit alternating sinusoidal magnetic fields into a region 30within which the head of patient 22 is located. By way of example,radiators 26 of assembly 24 are arranged in an approximately horseshoeshape around the head of patient 22. However, alternate configurationsfor the radiators of assembly 24 will be apparent to those havingordinary skill in the art, and all such configurations are assumed to becomprised within the scope of the present invention. The Carto®3catheter-based magnetic tracking system, produced by Biosense Webster,Irvine, Calif., is similar to sub-system 23.

Elements of system 20 are controlled by a system processor 40,comprising a processing unit communicating with one or more memories.Processor 40 may be mounted in a console 50, which comprises operatingcontrols 58 that typically include a keypad and/or a pointing devicesuch as a mouse or trackball. Console 50 connects to the radiators via acable and/or wirelessly, and also connects to other elements of system20, such as controller 52 of probe 28.

For the registration performed by system 20, just prior to its insertioninto eustachian tube 36, distal end 34 of ENT probe 28 is touched todifferent regions of the skin of patient 22. The signals induced in thesensor in response to its interaction with the magnetic fields enablethe position of distal end 34 to be tracked once assembly 24 has beencalibrated. A probe controller 52, held by a physician 54 operatingsystem 20, is connected to the proximal end of ENT probe 28, thecontroller allowing the physician to control acquisition of the signalsfrom sensor 32.

Processor 40 uses software stored in a memory 42 to operate system 20.The software may be downloaded to processor 40 in electronic form, overa network, for example, or it may, alternatively or additionally, beprovided and/or stored on non-transitory tangible media, such asmagnetic, optical, or electronic memory. In particular, processor 40runs a dedicated algorithm that enables processor 40 to perform thedisclosed position tracking and registration steps.

ENT Hollow Guidewire With Attached Balloon

FIG. 2 is a side-view of distal end 34 of the ENT probe 28 of FIG. 1inside eustachian tube 36, in accordance with an embodiment of thepresent invention. Distal end 34 is seen after being advanced through asmall diameter sheath 27 through which hollow guidewire 62 is insertedto eustachian tube 36 from the nasal cavity through an anatomicalopening 38. Hollow guidewire 62 has an exceptionally low diameter, onthe order of several hundred microns, while still being stiff enough, asdescribed below, to be inserted into a channel blocked by media such asdense mucus.

Balloon 60, which is attached to the distal edge of hollow guidewire 62,is navigated to and placed at a target location inside eustachian tube36 using magnetic position tracing sub-system 23 that tracks thelocation of magnetic position sensor 32. FIG. 2 further shows balloon 60inflated through hollow guidewire 62, dilating eustachian tube 36.

The example illustration shown in FIG. 2 is chosen purely for the sakeof conceptual clarity. FIG. 2 shows only parts relevant to embodimentsof the present invention. Other system elements, such as means foroptical imaging, or drug delivery, are omitted for clarity.

FIG. 3 is a schematic, pictorial illustration of distal end 34 of ENTprobe 28 of FIG. 2, in accordance with an embodiment of the presentinvention. In the shown embodiment, balloon 60 is glued to hollowguidewire 62 at a proximal perimeter 64 of a hole made in balloon 60through which hollow guidewire 62 was inserted into balloon 60.Guidewire 62, which is sealed at its distal edge, is going through theballoon with the distal edge exiting balloon 60. The balloon is glued tothe distal end of guidewire 62 over a distal perimeter (not shown). Byguidewire 62 protruding beyond balloon 60, physician 54 is able toadvance the still collapsed balloon (not seen) through a narrow channel.

Hollow guidewire 62 enables fluid to flow into the balloon through aside hole 65, as illustrated by arrows 66. Fluid, for example, salinesolution may be pumped into balloon 60, so as to inflate balloon to highpressure and then once desired, fluid may be pumped out of balloon todeflate the balloon.

In some embodiments, the wall of hollow guidewire 62 is made of athin-wall polyimide tube 62 a reinforced with a metal coil 62 b. In anembodiment, polyimide wall 62 a, or another suitable plastic, has themetal wire of coil 62 b braided in which serves to limit expansion ofthe tube due to high internal pressures while not limitingmaneuverability. Such a reinforced tube can withstand high-pressurefluid streaming inside the tube during a dilation procedure, and providethe required stiffness to overcome mechanical resistance for insertionof probe 28 into a channel, resulting, for example, from blocking mucus.

Balloon 60 is configured to remain in its dilated form and main a sameapproximate size (e.g., up to ±10%) over a wide range of internalpressure between a few atmospheres and fifteen atmospheres. This way,balloon 60 can be used for dilating narrow channels to a predetermineddiameter in a controlled and safe manner.

In some embodiments, the disclosed ENT probe includes magnetic positionsensor 32, which is used for tracking a location of balloon 60 (e.g.inside eustachian tube 36) during the ENT procedure. The disclosedmagnetic position sensor may contain a single-, double-, or triple-axismagnetic transducer. In order to conform with the small diameterrequired of distal end 34, magnetic position sensor 32 is formed on aflexible printed circuit board wrapped around the ultra-thin hollowguidewire, as noted above.

The example illustration shown in FIG. 3 is chosen purely for the sakeof conceptual clarity. FIG. 3 shows only parts relevant to embodimentsof the present invention. Additional elements, such as electrical wires,possible temperature sensors, and irrigation holes for infusion of adrug, are omitted for clarity of presentation.

FIG. 4 is a flow chart that schematically illustrates a manufacturingmethod of the ENT probe of FIG. 3, in accordance with an embodiment ofthe present invention. The process begins with fitting a reinforcedhollow guidewire 62 having a side hole 65 and an occluded distal endthrough proximal and distal holes in balloon 60 so that hollow guidewire62 protrudes beyond the balloon, in a balloon fitting manufacturing step70. Next, the protruding hollow guidewire is glued to balloon 60 over aproximal perimeter 64 and over a distal perimeter (not shown), at aballoon gluing manufacturing step 72. Alternatively, heat may be used tomelt proximal and or distal perimeters of balloon to exterior guidewiresurface. At a magnetic position sensor disposing step 74, magneticposition sensor 32 is wrapped around the distal end of hollow guide wire62, and glued together with its electrical leads (not shown).

The example flow chart shown in FIG. 4 is chosen purely for the sake ofconceptual clarity. Additional steps, such as connecting electricalwires to sensor 32 are omitted to simplify presentation. A more detaileddescription of steps of manufacturing is omitted for simplicity.

FIG. 5 is a flow chart that schematically illustrates a method fordilating an ENT channel, in accordance with an embodiment of the presentinvention. The medical procedure begins with physician 54 insertingballoon 60 into an ENT channel, such as eustachian tube 36, by advancinghollow guidewire 62, at a balloon insertion step 80. Next, physician 54uses system 20 to navigate and position balloon 60 at a blocked locationinside the channel, at a balloon positioning step 82. Physician 54 thendilates the channel by inflating balloon 60, by flowing high pressuresaline solution into the balloon through hollow guidewire 62, at aballoon dilation step 84. After physician 54 decides that the dilationsuffices, the physician deflates balloon 60, at a balloon deflation step86. Finally, physician 54 retracts balloon 60 from the ENT channel bypulling out hollow guidewire 62, at a balloon retraction step 88.

Although the embodiments described herein mainly address ENTapplications, the methods and systems described herein can also be usedin other applications, such as in minimally invasive procedures inneurology or cardiology.

It will thus be appreciated that the embodiments described above arecited by way of example, and that the present invention is not limitedto what has been particularly shown and described hereinabove. Rather,the scope of the present invention includes both combinations andsub-combinations of the various features described hereinabove, as wellas variations and modifications thereof which would occur to personsskilled in the art upon reading the foregoing description and which arenot disclosed in the prior art. Documents incorporated by reference inthe present patent application are to be considered an integral part ofthe application except that to the extent any terms are defined in theseincorporated documents in a manner that conflicts with the definitionsmade explicitly or implicitly in the present specification, only thedefinitions in the present specification should be considered.

1. A medical probe, comprising: a hollow guidewire for insertion into achannel of an organ of a patient; a balloon fixed to a distal end of thehollow guidewire, wherein the balloon is configured to be inserted intothe channel using the hollow guidewire and is further configured to beinflated by pumping of fluid through the hollow guidewire; and amagnetic position sensor fitted at the distal end of the hollowguidewire.
 2. The medical probe according to claim 1, wherein the hollowguidewire comprises a coil-reinforced polyimide polymer tube.
 3. Themedical probe according to claim 1, wherein the hollow guidewirecomprises a braid-reinforced polymer tube.
 4. The medical probeaccording to claim 1, wherein a distal edge of the hollow guidewireprotrudes beyond the balloon.
 5. The medical probe according to claim 1,wherein the magnetic position sensor is formed on a flexibleprinted-circuit-board wrapped around the distal end of the hollowguidewire.
 6. A manufacturing method, comprising: providing a hollowguidewire for insertion into a channel of an organ of a patient;attaching a balloon to a distal end of the hollow guidewire so that thehollow guidewire protrudes beyond the balloon; and fitting a magneticposition sensor at the distal end of the hollow guidewire.
 7. Themanufacturing method according to claim 6, wherein providing the hollowguidewire comprises providing a coil-reinforced polymer tube.
 8. Themanufacturing method according to claim 6, wherein providing the hollowguidewire comprises providing a braid-reinforced polymer tube.
 9. Themanufacturing method according to claim 6, wherein the distal edge ofthe hollow guidewire protrudes beyond the balloon and both ends of theballoon are secured to the distal end of the hollow guidewire.
 10. Themanufacturing method according to claim 6, and comprising securing bothends of the balloon to the hollow guidewire by gluing both ends of theballoon to the hollow guidewire.
 11. The manufacturing method accordingto claim 6, and comprising securing both ends of the balloon to thehollow guidewire by melting both ends of the balloon to the hollowguidewire.
 12. The manufacturing method according to claim 6, whereinfitting the magnetic position sensor comprises forming the magneticposition sensor on a flexible printed-circuit-board wrapped around thedistal end of the hollow guidewire.
 13. A method, comprising: insertinga balloon attached to a hollow guidewire into a channel of an organ of apatient, wherein the balloon is configured to be inflated or deflatedthrough one or more side holes in the hollow guidewire; navigating theballoon in the channel using a magnetic sensor fitted at the distal endof the hollow guidewire; and inflating the balloon by pumping fluidthrough the hollow guidewire to dilate the channel.
 14. The methodaccording to claim 13, and comprising deflating the balloon through thehollow guidewire, and retracting the balloon by pulling the hollowguidewire out of the organ of the patient.